Various puncture sealing preparations are available on the market. They mainly contain colloidal dispersions of polymers in an aqueous medium, known in the following as lattices. Thus, for example polystyrene butadiene lattices, poly (vinyl acetate) lattices, acrylic copolymer lattices, nitrile lattices and polychloroprene lattices are used. Sealing preparations are also known which do not contain water but rather tetrachloroethylene as the carrier medium.
The prior art uses, for the introduction of such sealing preparations into a tire and for pumping up the tire to a pressure at which it can be used, an apparatus comprising a pressure-tight container for the sealing preparation which contains a liquefied gas as a pressure source. This is referred to as a spray can in the following. A propane/butane mixture is mainly used as the liquefied gas. In rare cases, fluorochlorohydrocarbons are also used. These spray cans have a hose at their outlet valve, the other end of the hose being provided with a screw adapter for the tire valve.
When a tire puncture occurs, the sealing preparation is sprayed from the spray can into the interior of the tire through the tire valve and the tire is reinflated by means of the proplellant gas to a specific pressure which is of different levels depending on the leak. The tire is then driven a few kilometers, dependent on the nature of the defect, to distribute the sealing preparation in the interior of the tire and to seal off the defect.
In another apparatus, the sealing preparation is located in a compressible flask which is connected via an adapter to the tire valve with the valve insert having been previously removed. The sealing preparation is then sprayed into the tire by pressing the flask. After the insertion of the valve insert, the tire is then pumped up again to a specific pressure with the aid of carbon dioxide cartridges.
The previously used sealing preparations are not completely satisfactory. They can be mechanically removed relatively easily, some of them are not adequately effective in wet conditions and do not result in a seal when the tire defect is present at the edge of the breaker, i.e. at the edges of the tire treads.
Difficulties also arise with the prior art apparatus for introducing the sealing preparation into the interior of the tire and for pumping up the tire. Thus, with spray cans which contain propane/butane mixtures as the propellant gas, one can, depending on the mixture ratio, only satisfactorily operate to temperatures down to about 0° C. Furthermore, propane/butane mixtures are combustible and explosive. Fluorochlorohydrocarbons are a burden for the environment. Finally all known propellants are only available in a limited quantity when a puncture occurs.